Mobile machines are often needed in adverse conditions and on rugged terrain. One way to deal with these conditions is with the use of a track-type machine. A track-type machine utilizes articulating track chains to engage the ground and propel the machine. Since the track chains are the interface point between the machine and the ground, the track chains are directly exposed to destructive forces, such as abrasive mixtures of water, dirt, sand, rock and chemical elements. The track chains are also exposed to large forces and torques. Failure of a track chain can lead to significant losses in productivity. Consequently, manufacturers of track-type machines have sought to improve the durability of the track chains.
One method of improving track chain design and durability is disclosed in U.S. Pat. No. 6,739,680 (the '680 patent). The '680 patent discloses a cartridge assembly for a track chain assembly. The cartridge assembly of the '680 patent includes a bushing rotatably positioned about a track pin. Bearing members are positioned about the track pin adjacent the bushing. Collars are positioned about the track pin adjacent the bearing members. Seal arrangements are positioned between the collars and the bearing members and between the bearing members and the track bushing for excluding contaminants and retaining a lubricating fluid.
Although the device of the '680 patent may improve the durability of a track chain, it may still be improved further. For example, rotation of the bearing members relative to the bushing (e.g., when bushing is constrained from rotating due to contact with an external object) may produce galling in a side wall of the bushing over time. This disclosure is directed at overcoming the problems described above and/or other problems associated with track chains.